Prior art processes for making printed circuits and printed circuit boards typically use a silver halide polyester based film to create an image of a desired printed circuit along with several other steps and processes for forming and developing the printed circuit. A photo plotter is a piece of equipment that typically uses silver halide polyester film as the medium for imaging the design of a circuit. This equipment is then used in subsequent processing to image circuits for metallization or to print and etch specifically designed circuits. This is known as a print and etch process or a plate and etch process.
One example of a prior art process for forming printed circuit boards includes the steps of creating a CAD/CAM design, sending data relating to the design to a photo plotter, photo plotting to a silver halide polyester film, developing an image from the sent data, creating intermediate tools, scrubbing or cleaning substrate for imaging, coating the substrate with a dry film, imaging the substrate with the design, developing the image, etching the image, and then stripping the remaining dry film. This prior art process requires several steps and has limitations on the imaging, developing, and etching of fine line images. With this process, fine line imaging can be consistently performed down to 0.003 inches. Imaging of much finer lines, for example imaging fine lines down to 0.0025 inches, creates a problem and is inconsistent when using this prior art process. In addition, laminate must be purchased with copper adhered to a panel and this type of processing has inherent issues with undercutting and rough edges which can create “lossy” issues for high speed RF applications. In other words, with this process, any rough protrusions or undercutting act like small antennas and the signal travel speed is reduced or lost during high frequency applications. High frequency applications require smooth images and very thin copper.
Accordingly, there is a need for a new method for making printed circuits and printed circuit boards which facilitates fine line imaging without the inherent problem seen in the prior art processes. In addition, a method for making printed circuits and printed circuit boards is needed which will eliminate many of the steps used in prior art processes while still enabling the creation of printed circuits and printed circuit boards with fine line imaging, with very flat non-rough surfaces without undercut utilizing very thin copper, below 2 microns.